Free / open source games: A - C

There are more and more free / open source games: this list,
far from being exhaustive but continuously growing, gives priority to
projects that keep on being developed and is meant to help whoever is
looking for some fun.

All these open source games are free but remember that the
term free is
meant as in "free speech", not as in "free beer" so if you like one of
these games please try to contribute to its development: some teams
need varioul kinds of help (programmers, graphics experts...), some
accepts donations to finance the development of a game, some need help
to test new versions which means that you can have fun and at the same
time help the development of a project.

This is the first part of the list and included the games from
A to C: from the side menu you can access to all the other parts of the
list.

A3P

A3P is an indie online shooter that combines the best aspects
of the Third Person Shooter and Real-Time Strategy genres. A game
consists of 3 matches, and whoever wins 2 out of 3 wins the game. At
the beginning of each match, you receive money to purchase your weapons
and up to three units. Or you can save up for better stuff later on.

Advanced Strategic Command

Advanced Strategic Command is a free, turn based strategy
game. It is designed in the tradition of the Battle Isle series. It can
be played both against the AI and against other human players, using
hotseat or PlayByMail.

Aleph One

Aleph One is a FPS derived from the Bungie project
Marathon released as open source and expanded with a series of
maps, textures and more. There are also some "major conversion" with
different settings.

Anywhere Board Games (ABG)

Anywhere Board Games (ABG) is an open source web app intended to replicate the experience of a bunch of friends sitting around a table playing their favorite board and card games but on computers. It also supports games in a Google+ Hangout.

Apocalypso

Apocalypso is an arcade-style game where you play as Dirk
Dirtland
as he tries to defend a city from a robot invasion. Enemies will attack
both from far away as well as from inside the city, so Dirk will have
to use both his weapon and his flexible shield as well as enhance his
abilities through different upgrades in order to fend off all attackers
and live to tell the tale.
5 different levels, each with a
different tactical situation and a unique boss awaits our hero as he
fights to save the remnants of a lost world.

Ardentryst

Ardentryst is an RPG set in a fantasy world with elemnts
inspired to other games such as Donkey Kong
Country, Mario, Castlevania and Kingdom Hearts. The player is
guided through a storyline which he or her must act in
and play a major role in keeping peace and order in Ardentryst

Armagetron Advanced

Armagetron Advanced is a 3D multiplayer game that emulates and
expands the light cycle, the futuristic motorbyke from the movie Tron.
The arenas can be modified and there are various play modes, also
online

Asgard

Asgard is a project aiming to create a classic computer role-playing game experience complete with epic battles, an expansive world map, towns, cities, and vile lairs all provided through vibrant graphics, compelling music, and an intriguing plot.

Atomic Tanks

Atomic Tanks is a Scorched Earth clone with
similarities to the Worms series. Annihilate the other tanks
to earn money, then spend it on bigger and better shields and weapons
to wipe out the opposition.

Batrachians

Batrachians is a game where you control a frog. Your goal is to eat more flies and score more points than the computer's frog. It is a clone of the 1982 Frog Bog video game for the Intellivision by Mattel Electronics.

Beastlands - Song of the Were

Beastlands - Song of the Were is a lightweight hack and slash adventure game with some RPG and RTS elements. It is based on Tanir's Quest's engine. The story of the game is based on the Beastlands plane of existence where sylvan creatures make up most of the population. Ehlonna, Godess of nature, daughter of Gaia leads a party of hers through the wilderness on a quest against evil intent together with her Brother Dieties.

Blob Wars: Blob And Conquer

Blob Wars: Blob And Conquer is a sequel of old arcade Blob
Wars:
Metal Blob Solid. In this new episode, which unlike the first
one
is a 3D game, the protagonist discoveres that hishomeworld is still
littered with the alien force and he must fight them.

Blood Makes the Grass Grow Green

Blood Makes the Grass Grow Green (BMTG3) is a
side-scrolling or 1-dimensional strategy game that pits two people
against each other in a duel over a stretch of land. Each player is
positioned in a bunker at opposite ends of the map and tasked with
deploying the right personnel and vehicles to capture FOBs (forward
operating bases) and overrun your enemies bunker.

Bombic 2

Bombic 2 is a bomb game like Dyna Blaster. It has lots of creatures and bonuses. You can play alone against creatures as with friends in cooperative mode. The game provides also a deathmatch for 2 to 4 players on one computer. It also includes a map editor.

Brain Party

Brain Party is a fun, free puzzle game for all the family that's made
up of 36 minigames designed to push your brain to its limits by testing
memory, logic, mathematics, reaction time and more! Brain Party is
split into two modes: test mode gives you five minigames in a row and
adds up your brain weight to see how smart you are, and practise mode
lets you play your favourite minigames as often as you want. If you do
well enough, there are six extra minigames that can be unlocked as well
as a new game mode designed to keep you playing and enjoying your
favourite games even longer.

BrisKola

Brogue

Brogue is a Roguelike game that is a direct descendant of Rogue, unlike other popular modern roguelikes, and it favors simplicity over complexity, while trying to ensure that the interactions between components will be interesting and varied.

BurgerSpace

BurgerSpace is a game in which you are a chef, and must walk over hamburger ingredients (buns, meat, and lettuce) to make them fall from floor to floor, until they end up on the plates at the bottom of the screen. It requires the SDL multimedia library. It is a clone of the 1982 BurgerTime video game by Bally Midway.

The Butterfly Effect

The Butterfly Effect is a physics game about cause and effect. You build complex mechanical systems using levers, rocket-like cola bottles and ordinary objects like tennis balls and bikes to accomplish simple tasks like toppling a Bowling Pin.

Cataclysm: Dark Days Ahead

Cataclysm: Dark Days Ahead is a roguelike set in a post-apocalyptic world. Surviving is difficult: you have been thrown, ill-equipped, into a landscape now riddled with monstrosities of which flesh eating zombies are neither the strangest nor the deadliest.

Chess III Arena

Chess III Arena is a simple chess game that utilizes Quake III Arena .md3 models for the various pieces. If you don't have Quake III Arena you can use Open Arena free models instead. Chess III Arena can optionally be configured to play a computer opponent via gnuchess.

Chroma

Chroma is an abstract puzzle game. A variety of colourful
shapes are arranged
in a series of increasingly complex patterns, forming fiendish traps
that must
be disarmed and mysterious puzzles that must be manipulated in order to
give
up their subtle secrets. Initially so straightforward that anyone can
pick it
up and begin to play, yet gradually becoming difficult enough to tax
even the
brightest of minds. It features:

Chromium B.S.U.

You are captain of the cargo ship Chromium B.S.U., responsible
for delivering supplies to our troops on the front line. Your ship has
a small fleet of robotic fighters which you control from the relative
safety of the Chromium vessel.

Connectagram

Connectagram is a word unscrambling game. The board consists
of several
scrambled words that are joined together. You can choose the length of
the words, the amount of words, and the pattern that the words are
arranged in. The game provides a hint option for times when you are
stuck, and features an online word lookup that fetches the definitions
of each word from www.dict.org.
Your current progress is automatically saved.

Cosmosmash

Cosmosmash is a game where you control a base that must destroy rocks before they hit the ground, or you lose points. You must also prevent "spinners" from touching the ground, or your base will explode. This game is a clone of the 1981 Astrosmash video game for the Intellivision by Mattel Electronics.

Cube Escape

Cube Escape is a game that starts with you inside a
cube made up of numerous shells, with a maze etched on the surface of
each shell. Escape the cube by traveling through the mazes, including
over cube edges, until you find an upward exit. When you reach the red
exit, you win.

Cube Trains

Cube Trains is a puzzle game where you build elevated railways in a city. It features 3D puzzles, unlimited undo/redo, and smart placement of pieces. The non-linear level graph means you don't have to beat a level before unlocking the next one. The game comes with a built-in level editor, so you can build and share your own corners of the city.

Cuby

Cuby intents to be a logic puzzle game.
You control a 3D cube with your mouse. Click on a colored block and
drag along the empty spaces to create a line that connects the pair.
There are a bunch of levels in different sets. Detailed help about how
to play and an editor to create new levels is included within the game.

CuteMaze

CuteMaze is a simple, top-down game in which mazes are
randomly
generated using one of a choice of several different algorithms. You
move the character through the maze while hunting for targets (cheese,
by default)—the game is won once all of these targets have
been picked
up.

Cytadela

Cytadela is the conversion of the FPS for AmigaOS
with the same
name. The goal of the game is to find six bomb parts with which the
Citadel has to be blown up. To achieve it, the player not only has to
defend himsefl against the enemies, but (s)he also has to solve many
riddles, such as swithcing apropriate buttons in order to open some
door, move some walls, etc.